March 12 (Bloomberg) -- Anthera Pharmaceuticals Inc.
plummeted 45 percent after canceling a late-stage trial of an
experimental treatment for heart disease because it didn’t work.

Anthera declined to $3.56 at the close of trading, for the
biggest single-day drop since the Hayward, California-based
company first sold shares to the public in March 2010.

Anthera closed enrollment in the study and told
investigators to immediately remove patients from the therapy,
varespladib, the company said in a statement on March 9. The
treatment was being used with cholesterol-lowering drugs to
prevent a recurrence in patients who had suffered from acute
coronary syndrome, Anthera said on its website. Varespladib was
in the third and final stage of clinical testing generally
needed for regulatory approval.

“This new information was totally unexpected and
disappointing given the potential benefits of this drug,”
Stephen Nicholls, chairman of the executive committee overseeing
the trial, said in the statement.

Acute coronary syndrome is an umbrella term that covers a
range of medical issues involving blood blocked from the heart,
such as heart attack, according to the American Heart
Association.

With varespladib’s failure, the company’s lead drug is now
blisibimod, a therapy for systemic lupus in the second stage of
testing that will face a challenging market, Steve Scala, an
analyst at Cowen & Co. in Boston said today in a note to
clients.

“A poorly defined lupus market and disappointing sales of
novel agents in this space further temper our enthusiasm,” he
wrote.